The present invention relates to surgical tape, and in particular, to breathable surgical tape having substantially uniform strength in all directions.
Breathable surgical tape is gaining increasing acceptance for closure of skin incisions and wounds that formerly required stitching. When used for skin closure, the tape must have sufficient breaking strength and adhesion strength to withstand normal shear stresses and maintain wound security. The tape must also be permeable to air and water vapor, in essence, to allow the skin to "breathe". The tape should have structural characteristics which permit skin conformability, promote resistance to curling and promote delocalization of longitudinal stresses at opposed ends of the tape, as will be explained further below. Finally, the tape should resist accumulation of debris on its outer side.
A general object of the present invention is to provide a breathable surgical adhesive tape having the desired tape characteristics mentioned above.
More specifically, it is an object to provide such tape having a breathable, unitized filamentous backing which is strong in all dimensions, is skin comformable, resists curling and promotes delocalization of longitudinal stresses in the tape.
Another object of the invention is to provide such tape having a backing laminated with a porous adhesive layer which is permeable to air and moisture and provides good adhesive strength.
Still another object of the invention is to provide such tape wherein the adhesive layer, which is somewhat fluidic, is substantially confined to one side of the tape backing.
Yet another object is to provide a method of forming a surgical tape having the above characteristics.
These objects are realized in a surgical tape having a backing formed of continuous polymeric filaments which are randomly oriented in a plane, and fused together at filament crossover points. Adhesively bonded to the filaments in the backing, on one side thereof, is a porous layer of pressure-sensitive adhesive.
In a preferred embodiment of the invention, the backing is composed of nylon filaments which are fused together in a molten state. The spacing between adjacent filaments is generally less than a specified dimension, preferably about 10 to 15 mils. The adhesive layer is composed of fibers embedded in a planar expanse of pressure-sensitive adhesive, these fibers having lengths substantially gretaer than the above-mentioned interfilament spacing dimension, thus to limit penetration of the adhesive layer into the backing.
Also disclosed herein is a method for forming a tape having the above-described structure and characteristics.